The broken anti-wrap bar....

SHavis

 
 
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This was holding a 14B in place. This breakage preceded the drive shaft binding and the springs going S shaped. (then the front end falling apart trying to get out) I've not seen anything like this. And, yes, my foot was in it. Last ledge on Box Canyon at Superlift ORV park at the Southern Cruiser Crawl. There had to be a tremendous amount of tension on this. The upper bushing sleeve is oval now and that weld is showing signs of failure. I now have a serious respect for the loads placed on the means of locating the rear axle.

I'm looking seriously into four linking the rear now.

Cheers!

IMG_7834.JPG
 
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mr jits

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This was holding a 14B in place. This breakage preceded the drive shaft binding and the springs going S shaped. (then the front end falling apart trying to get out) I've not seen anything like this. And, yes, my foot was in it. Last ledge on Box Canyon at Superlift ORV park at the Southern Cruiser Crawl. There had to be a tremendous amount of tension on this. The upper bushing sleeve is oval now and that weld is showing signs of failure. I now have a serious respect for the loads placed on the means of locating the rear axle.

I'm looking seriously into four linking the rear now.

Cheers!

View attachment 1825386
Sorry about the carnage, but you've gotta be a bit proud!!
 

bugsnbikes

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Not surprised it broke in the heat affected zone. It’s always hard to know how well it was welded or if too much heat caused the start of fail zone.
 

SHavis

 
 
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lower bar needs to be made out of .250 wall
Most definitely. This one is more like .120. I'm going to do something different as she goes back together. I just got the D60 front in last weekend. After I finish tweaking that, I have another 14b housing to start welding truss brackets onto. But my internal dilemma is do I just throw on another track bar or spend that time fabbing up a four link? Which will take much longer and that means less time out on the trail. decisions...

Not surprised it broke in the heat affected zone. It’s always hard to know how well it was welded or if too much heat caused the start of fail zone.
I didn't think of that, but I suppose that area could have been make a bit more brittle and prone to fracturing. I am really surprised that the tubing pulled apart before the hiem joint. The hiem and connection looks nearly new.

Cheers!
 
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What is the pipe wall thickness? I think you are supposed to have the middle support at an angle to load the main tubes horizontally rather than vertically. Not sure on that though. Also your separation on the axle end looks kinda narrow. I had the same problem using bushings ovaling out. I use Heims at all 3 points now. Here is a fcfab traction bar...
IMG_4967.jpg

Here is one I made, I didn't bother with middle supports because the pipe wall I used is pretty thick. I think it's 3/8 wall if I remember.
20171011_205443-1612x1209.jpg
 
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mr jits

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Most definitely. This one is more like .120. I'm going to do something different as she goes back together. I just got the D60 front in last weekend. After I finish tweaking that, I have another 14b housing to start welding truss brackets onto. But my internal dilemma is do I just throw on another track bar or spend that time fabbing up a four link? Which will take much longer and that means less time out on the trail. decisions...



I didn't think of that, but I suppose that area could have been make a bit more brittle and prone to fracturing. I am really surprised that the tubing pulled apart before the hiem joint. The hiem and connection looks nearly new.

Cheers!
If you're starting from a bare housing, a four link shouldn't take you more than a solid weekend's worth of work.
 

SHavis

 
 
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If you're starting from a bare housing, a four link shouldn't take you more than a solid weekend's worth of work.
It's not really bare, yet. It still has all the old brakes and brackets, and spring pads attached. Plus I have a tendency to overthink. You know, grab a beer, and stare at the job for a bit pondering what goes next. You must work really fast! I'd need a weekend just to get the housing prepped and shaved. ;)

I'm really leaning toward the 4 link. I already have the shock mounts high up and tied to the cage and a sway bar. Been reading about springs. Wow, I had no idea coil over springs were complicated. But they are.

Cheers!
 
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4 link, put your instant center at the center of the weight of the vehicle and stun those who think gravity works different off-road. You're fortunate you didn't twist your axle tube or break the center section...
 

SHavis

 
 
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4 link, put your instant center at the center of the weight of the vehicle and stun those who think gravity works different off-road. You're fortunate you didn't twist your axle tube or break the center section...
I did a 4 link on my old '65 and it was great! But the tub was off and that made it so much easier. Used Aerostar van front springs (this was 15+ years ago). I had no idea about how-to, I just did what fit with materials on hand. I'll put some more research into it this time. Looking back, I don't think it's as stout as it needed to be. Odd thing, maybe you know why, but under load, the rear end lifted a bit, rather than the front. I had fairly short bars on top.

I found an old thread that had some pics here: Rear 4-Link with Coil Springs - Page 2 - Pirate4x4.Com : 4x4 and Off-Road Forum

P1010209.JPG
 

Mace

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The reason for your rear end "lifting" when you accelerate is Antisquat. You had a reasonable amount of it.. It's also what makes you hop a bit when doing vertical climbs.
 

SHavis

 
 
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The reason for your rear end "lifting" when you accelerate is Antisquat. You had a reasonable amount of it.. It's also what makes you hop a bit when doing vertical climbs.
I'm guessing longer, and more parallel with the frame, upper arms would fix that. Ideally, the uppers and lower imaginarily meeting at the center of gravity (instant center). Is that right? In my case, I think that point will have to be a little below and behind the CG if I keep the upper arms horizontal.

Cheers!
 
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I did a 4 link on my old '65 and it was great! But the tub was off and that made it so much easier. Used Aerostar van front springs (this was 15+ years ago). I had no idea about how-to, I just did what fit with materials on hand. I'll put some more research into it this time. Looking back, I don't think it's as stout as it needed to be. Odd thing, maybe you know why, but under load, the rear end lifted a bit, rather than the front. I had fairly short bars on top.

I found an old thread that had some pics here: Rear 4-Link with Coil Springs - Page 2 - Pirate4x4.Com : 4x4 and Off-Road Forum

View attachment 1826030
if you draw an imaginary line that follows the upper link towards the front of the vehicle, then a line that follow the lower link - where those two lines meet is where the force from the rear axle will 'lift' the vehicle. If it is behind the vehicle's center of the weight of the vehicle, it will naturally cause separation between the axle and the frame. Conversely, if that point is in front of the center of weight, it will cause the vehicle to lift that point which will plant more weight on the rear axle. There are reasons to put that point where the forces lift the vehicle in either point. It all depends on how you wish to use the vehicle. That point where it lifts is called the instant center.

I took this picture at SEMA because this vehicle would be terrible to drive... it's instant center is at the behind that cross member.... yet there are lots of people who have no clue how to set up or design suspensions - and wouldn't know that it could be so much better.


My '40 lifts about where the bottom of the flywheel is. Its CG is as low as possible while keeping a flat undercarriage. The IC is just a touch behind the center of the weight because I want the rear to separate just a bit when I nail the throttle.... mostly because when I'm climbing a steep hill, the last thing I want to do is bring the nose closer to vertical.
 

matzell

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I keep reading the word "pipe". Are you guys using pipe or DOM. It should be made of DOM. Much stronger and less brittle. If it was pipe I can see why it failed.
 
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